Chinese scientists and health experts involved in the country's fight against the coronavirus believe the worst is now over, downplaying warnings that the disease could become seasonal or that a deadlier "second wave" could hit later in the year.
As the pandemic continues to spread overseas, a growing number of countries are bracing themselves for a worst-case scenario in which Covid-19 remains in circulation until next year at the earliest.
But medical advisers in China have expressed confidence that the country's strict containment measures have done enough to ensure that the outbreak can be brought under complete control, domestically at least, within weeks.
Though they remain wary of the risks of "importing" cases from overseas, they say China should be capable of eliminating Covid-19 in the same way it eliminated Severe Acute Respiratory Syndrome (SARS) in 2003. SARS was eventually contained after the government imposed stringent screening and quarantine measures.
"For me, a second outbreak (of coronavirus), a domestic outbreak in China, wouldn't be a great concern," said Cao Wei, deputy director of the Department of Infectious Diseases at the Peking Union Medical College Hospital.
She told a briefing on Monday that while China needed another month to make a final judgment, the existing prevention and control measures should be enough to bring the epidemic to an end domestically.
The World Health Organization said the coronavirus reached a peak in China around late February.
Zhong Nanshan, a senior government adviser who helped detect and defeat SARS in 2003, said it "could be over by June" if other countries take the required action.
On Wednesday, there were no new domestic cases in the disease's epicentre of Wuhan for the first time since the outbreak began. However, "imported" infections reached a record 34, and have outnumbered domestic transmissions for five consecutive days.
Ian Henderson, director of the Institute for Molecular Bioscience at the University of Queensland, said China's actions to contain the virus have been "extraordinary" but there could be a second outbreak, this time imported.
"(What) remains possible is that as controls around isolation are relaxed in China , with a population that is still susceptible, then the virus may resurge if it has not been eradicated elsewhere," he said.
Done '99 out of 100' steps
Gao Zhengliang, vice-director of the China Cell Biology Institute told the official Youth Daily newspaper that the country had now completed "99 out of 100 steps" required to defeat the coronavirus, though he warned that if global infections spiralled out of control, "the costs and sacrifices China has made will be downgraded."
Some experts have referred to the infection patterns of the devastating 1918-19 influenza epidemic that killed more than 50 million people during three different waves, with the second the deadliest.
However, Henderson said it was important to recognise the current virus was different from influenza.
Can we become immune to Covid-19?
Global inter-connectedness means that instead of coming in waves, new viruses are now more likely to spread and circulate until they mutate or until a certain level of immunity is reached. One crucial issue is how long a previously infected patient remains immune.
"The number one point to get across is that in terms of the behaviour of this virus we are still very much in the dark," Henderson said.
"The issue around protective immunity is difficult to answer because we simply do not have sufficient information."
Some experts have raised the possibility that Covid-19 could become an entrenched seasonal illness along with ordinary influenza.
Covid-19 might be here to stay
Preliminary studies have shown a possible correlation between the epidemic and climate patterns. A paper produced by researchers in Europe this week said the coronavirus preferred cool and dry conditions which could lead to seasonal global outbreaks "much like other respiratory diseases".
However, there have still been cases in warmer and more humid climates in southeast Asian countries, including Thailand and Singapore.
US President Donald Trump has been one of many to suggest that Covid-19 could go away of its own accord as temperatures rise in the northern hemisphere.
However, Marc Lipsitch, a communicable disease expert at the Harvard TH Chan School of Public Health, said while warmer and wetter weather could reduce the contagiousness of the coronavirus, "it is not reasonable to expect those declines alone to slow transmission enough to make a big dent."
Gao of the China Cell Biology Institute said given the higher fatality rate for the coronavirus, relaxing curbs was not an option.
"The resolute curbs on the coronavirus must be continued, it absolutely cannot be allowed to co-exist with humans in the same way as the influenza virus."
US anti-virus controls
Factories in China, struggling to reopen after the coronavirus shut down the economy, face a new threat from US anti-disease controls that might disrupt the flow of microchips and other components they need.
The shock threatens to set back the ruling Communist Party's efforts to revive the world’s second-largest economy after it declared victory over the outbreak. It would add to pressures on global business activity as Western countries close workplaces, limit travel and tell consumers to stay home.
Chinese manufacturers assemble more than 80 percent of smartphones for Apple, Samsung and other brands, half of the world’s personal computers and a big share of home appliances and other goods.
But they need US processor chips and other high-value components.
It isn’t clear how US anti-coronavirus curbs might affect trade. Controls so far apply to travellers, not goods. American factories are operating, but the National Federation of Independent Business says 39 percent of 300 companies it surveyed already were suffering supply disruptions.
“A sustained disruption of activity in the US will likely lead to disruptions to manufacturing activity in China,” said Darren Tay, a country risk analyst for Fitch Solutions, in an email.
Small companies at higher risk
Beijing is easing controls that left city streets empty and silent and sent shock waves through the global economy.
Manufacturers are rebuilding supply chains – networks of thousands of providers of auto parts, microchips and other components.
Officials say steel makers and other state-owned industries are almost back to normal. But conditions are more precarious for small, private companies that are China's economic engine and make clothes, toys and other consumer goods. Many are running at a fraction of normal levels or are closed due to a lack of materials and employees.
One in six companies that responded to a March 9-14 survey has run out of components and others are running low, the American Chamber of Commerce in South China said in a report Wednesday.
The US, Europe and other Asian countries accounted for 18 percent of shortages, the chamber said. It said supply chains from the US are suffering the second-biggest disruption after those in China.
Just over half the 237 companies surveyed were American and three-quarters were manufacturers. All reported “some impact” due to supply disruptions due to the outbreak.
Economists who have slashed forecasts of this year’s global economic growth cite disruption to Chinese and US manufacturing as one reason.
The predicament highlights the risks of manufacturing strategies that cut costs by using far-flung networks of suppliers and factories across multiple countries.
Smartphone brands likely will be hard-hit due to their reliance on Chinese assembly and fragmented groups of components suppliers, according to IDC.
Germany, Japan and South Korea also supply microprocessors and other smartphone components, but the most advanced chip producers are American.
Huawei Technologies Ltd, a Chinese maker of smartphones and network equipment, has said it expects no change in its supply chain in the next three to six months.
The company scrambled to remove American components from its products last year after President Donald Trump imposed curbs on access to US technology.
Automakers also are “highly exposed” because they need components from US and other global suppliers, Moody’s Investors Service said in a report. It said disruption in China would affect the worldwide industry.
